Many applications require the manipulation of data residing in data packets. For instance, packet processing in voice applications require the manipulation of several layers of protocol headers and several types of protocols. Also, protocols such as Internet Protocol (IP), Asynchronous Transfer Mode (ATM), and ATM adaptation layers (AALs) require header manipulation and error detection.
In the prior art, reduced instruction set computation (RISC) processors are used to perform manipulation of packet data. However, processors typically require many clock cycles to perform complex data manipulation. In addition, because processors typically operate on fixed length words, some inefficiencies result when the data to be manipulated is less than or more than the length of the word.